The present invention relates generally to grain dryers which utilize heated air to reduce the moisture content of harvested grain such as corn, beans, wheat, and oats.
In order to store grain for a long period of time, it is necessary to dry the grain to a condition in which it is less subject to molding or other deterioration. Accordingly, numerous types of grain dryers have heretofore been designed which possess a number of grain flow channels defined between a pair of perforated walls. Grain is advanced through these grain flow channels while at the same time heat is passed through the perforated walls. This process results in heating of the grain which is flowing through the grain flow channels thereby reducing the moisture content of the grain. Reducing the grain's moisture content enables the grain to be stored for a long period of time without molding or otherwise deteriorating.
Defined within the lower portion of the perforated walls of the above type of grain dryer, there exists a number of discharge slots through which grain advances after being subjected to the above-described moisture reduction process. One type of grain dryer which has heretofore been designed provides a grain shelf floor which receives the grain flowing out through the discharge slots. The grain shelf floor has a hopper opening defined in a center portion of the grain shelf floor. Thereafter, a grain metering system which includes a number of augers advances the grain from the outer portion of the grain shelf floor to the hopper opening. Once the grain reaches the hopper opening, the grain falls into a discharge hopper located under the hopper opening. The discharge hopper directs the grain to a discharge auger thereby removing the grain from the grain dryer.
One challenge when designing grain dryers is to obtain a grain metering system which is durable yet relatively inexpensive to manufacture. Another challenge when designing grain dryers is to obtain a grain metering system which accurately meters the grain into the discharge hopper at a desired rate. Yet another challenge when designing grain dryers is to obtain a grain metering system which has a relatively low horsepower requirement for the motor of the grain metering system. In addition, another challenge when designing grain dryers is to obtain a grain metering system that protects the motor of the grain metering system from being contaminated by grain dust. Still another challenge when designing grain dryers is to obtain a grain metering system which does not cause damage to the grain as the grain is metered into the discharge hopper. Yet another challenge when designing grain dryers is to obtain a grain metering system which does not cause damage to the grain shelf floor during operation of the grain metering system.